1. Field of the Invention
This invention relates to novel deodorizing additives for animal litters and the litter compositions containing such additives.
2. Information Disclosure Statement including Description of Related Art
The following information is disclosed in accordance with the provisions of 37 CFR 1.56, 1.97 and 1.98.
As is well-known, many species of animals and birds are raised and/or kept by people for various purposes, e.g., as pets; for the production of valuable products such as food or furs; or for experimental purposes. A major problem connected with the raising and/or keeping of animals is the disposition of their waste excretions, mainly urine and feces. Whether the animal or bird is caged, in which case its waste is deposited on the floor of the cage, or allowed to roam free but is trained to deposit its waste in a particular receptacle, a "litter" material is generally employed which is capable of absorbing the liquid portion of waste excretions, primarily urine and the excess liquid of fecal matter. However, while the water absorption properties of most litters make them effective in reducing the mess of animal waste excretions they do little to prevent the foul odor emitted by the waste.
Various deodorizing agents have been recommended for use in animal litters, including sodium bicarbonate (SBC). However, when SBC is utilized in the form of an unmodified powder as a deodorizing agent in animal litter, it tends to "wick" and dissolve in the aqueous phase of any animal waste products present, in which dissolved state it does not exert any deodorizing effect. Furthermore, due to its relatively high density, it tends to sink to the bottom of any litter composition present in the cage or litter box. To overcome these disadvantages, it has been proposed that the SBC be utilized in the animal litter in encapsulated form. However, the preparation of encapsulated SBC is an expensive procedure which renders the employment of SBC in this form impractical for many applications.
The following prior art references illustrate aspects of the technology of animal litter preparation.
U.S. Pat. No. 3,765,371 issued Oct. 16, 1973 to Fisher discloses a foamed plastic for absorbing and/or adsorbing animal waste products.
U.S. Pat. Nos. 4,275,684 issued Jun. 30, 1981 and 4,395,357 issued Jul. 26, 1983 to Kramer et al., disclose calcium silicate as an animal litter box absorbent material.
U.S. Pat. No. 4,315,761 issued Feb. 16, 1982 to Larrson et al., teaches the use of aerated or foamed concrete to absorb animal waste products and facilitate the removal of excrement from a litter box.
U.S. Pat. No. 4,494,481 issued Jan. 22, 1985 to Rodriguez et al., discloses the addition of a soluble salt of a transition metal from Group Ib or IIb of the Periodic Table added to a conventional litter composition to prevent the development of urine odors.
U.S. Pat. No. 4,570,573 issued Feb. 18, 1986 to Lohman, discloses an animal litter composition containing 60-94 wt. % of paper, 1-35 wt. % of gypsum, and 3-12% of water.
U.S. Pat. No. 4,638,763 issued Jan. 27, 1987 to Greenberg, teaches the addition of sodium sulfate to a litter box absorbent material to facilitate removal of solid absorbent material from the litter box.
U.S. Pat. No. 4,685,420 issued Aug. 11, 1987 to Stuart, discloses an animal litter composition comprising a water-absorbing polymer such as a polyacryate combined with a porous inert solid substrate.
U.S. Pat. No. 5,000,115 issued Mar. 19, 1991 to Hughes, discloses the use of a water swellable bentonite clay as an absorbent litter material. The clay absorbs the liquids in animal waste which on contacting the clay agglomerates it into a stable mass easily separated from the unwetted and unsoiled portion of the composition.
Application Ser. No. 08/056,629, filed May 3, 1993, discloses and claims litter compositions containing the deodorizing additive of this invention.